Electric switch.



J. H. HALL.

ELECTRIC swncn. APPLICATION FILED SEPT. 26, I910.

Patented May 4, 1915.

4 SHEETS-SHEET 1.

J. H. HALL.

ELECTRIC SWITCH.

APPLICATION FILED SEPT. 26. 1910.

Patented May 4, 1915.

4 SHEETS-SHEET 2- wmassss 6AWM 'J. H. HALL.

ELECTRIC SWITCH.

APPLICATION FILED SEPT- 29. 1910.

1,138,212. Patented May 4, 1915.

4 $HEETSSHEET 3- FIG. 5

' INVENTOR WITNESSES 0 {Z MM I x Q J. H. HALL.

ELECTRIC SWITCH. v APPLICATIONflLED SEPT-ZB iQIO- K Patented May 4, 1915.

4 SHEETS-SHEET 4.

FIG. 1

lllllllllllll A WITNESSES INVENTOR TE sra'rns PATENT cannon.

H. HALL, OF CLEVELAND, OHIO, ASSIGNOR TO THE ELECTRIC CONTROLLER AND MANUFACTURING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

ELECTRIC SWITCH.

Specification of Letters Patent.

Batented my 4, 1915.

Application lfiled September 26, 1910. SeriaI No. 583,747.

To all whom it may concern:

Be it known that I, JAY H HALL, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented new and useful Improvements in Electric Switches, of which the following is a specification.

My invention relates to electric switches, particularly to such magnetically-operated switches as are used to make the various connections in a motor circuit. In the usual motor control system one or more auxiliary con-- tacts are used on each switch for controlling the actuating circuits -of the switches, and some form of relay device is used to obtain automatic acceleration of the motor.

The objects of my invention are'1st. To provide switches by which the motor may be reversed and controlled without the use of auxiliary contacts or relay devices to contro'l the actuating circuits of the various switches. 2nd. To provide switches for accelerating the motor automatically by a control responsive to the current in the motor circuit and under the control of the operator without the use of the usual relay devices.

I will now describe my invention in detail, referring to the accompanying draw- -1ngs, 1n Wl'llCll- Figure 1 1s a wiring diagram embodying my invention. -Figs. 2 and 3 show in section and elevation the form of reverser switch which I prefer to use. Figs. 4 and 5 show in section and elevation one form of ac, celerating switch, and Figs. 6 and 7 show in section and elevation w an accelerating switch, in which the energizing windings are differently arranged.

Referring first to Figs. 2 and 3 which show the form of reverser which I prefer to use, d is a frame of magnetic material hav ing two parallel members provided with the two bosses or poles (Z and (Z3 on opposite sidesof the armature (Z which is pivoted between the said members on the pin (Z and is arranged to be attracted to one boss or the other. The arn'iature (1* carries two insulated contacts (Z and (Z supported on the insulating members d These contacts connect on one side with the stationary contacts (i and (,Z, and on the other side with the stationary contacts (Z and c (Fig. 1). The stationary contacts are mounted on an insulating support as also are the terminals 1. and; v (Z joined by the flexible connectors f to the, S The shoulder S on the rod S rests on 110 contacts (Z and d. The bosses d andd are surrounded by the windings al and d, re-

spectively;' and the boss to which the armature d" is winding (Z From Fig. 1 it is seen that the windings (1 and 03 are connected in seriesacross the supply mains as follows: frpm the positive main through the wire 1, the Contact 03", the winding d the point 0, the winding d,

pivoted surrounded by the the cont-acts cl and 03, the wire 5 and the The motor-field F to the negative main. winding 61 is in the armature branch of the motor circuit, as will be presently explained, so that each reversal of the armain the winding, the object of this coil being to prevent'the operation of the reversing switchwhen any motor current is flowing through it. Thewinding (Z has one terminal connected to the contact (Z and the other to the movable contact of the inain switch S, which is actuated by the winding S. The Winding S has one terminal connected to the wire 17 leading to the segments m" and m of the master switch WI, and the other terminal connected to the wire 13 or r ture rotation Wlll reverse the flow of current i other connection leading to the contact (Z 1, so

and spaced apart so as to receive between them the body'of the plunger or armature S and provide at opposite sides thereof the air gap 5 next to the boss S, and the, air gap S next to the boss S The latter boss is preferably the inner end of the plug S screwed into the side of the frame S By meansof this plug the air grip S -may be made greateror smaller. The boss i 3 may be made also adjustable. The plug S has a non-magnetic bushing S in which the lower reduced end S of the plunger reciprocates, The plunger body is connected by the rod ofnon-magnetic material S to the switch arm S pivoted to the frame S at the pin 53" and arranged to engage the fixed brush er contact S also secured to the support the frame and prevents the plunger S from falling beyond a fixed limit. The winding S surrounds the plunger S at or near the place where it changes its cross-section, thatand the other terminal connected to the mov-' able member of the switch which it actuates and to one terminal of a section of resistance. The windings S S and S2017 have each one terminal connected to the wire 13 and their three remaining terminals 0011-.

nectcd to the segments m m", and m, respectively, of the master switch M.

It has been found that the switch shown in Figs. i and 5 has the remarkable property of retaining its 'contacts open when the winding S is excited beyond a predetermined value and 011 causing its contacts to close when the excitation in the winding is lowered to that value. I have found that with the winding S excited a "cry small amount of excitation of the winding S will cause the magnetic pull on the armature S to be greater in the gap S than the diflerence between the force of gravity and the magnetic pull inthe gap S for any excitation of the coil S that can operate the switch arm; but if the winding S has operated the switch, the excitation of the winding S cannot cause the switch to open unless its excitation is very large. This effect is obtained when the flux set up by the winding S opposes the flux set up by the winding S Therefore, a small amount of excitation in the winding S prevents the switch from operating regardless of the amount of current flowing in the winding S. The armature S is restrained by gravity from operation until the magnetic pull across the'gap S exceeds that across the gap S by an amount sufficient to lift the said armature and parts connected thereto. The winding S when energized at a value higher than a predetermined value assists gravity or its equivalent to restrain the armature from movement. Obviously the restraining force may consist of equivalents of the force of gravity.-

In Figs. 6 and 7 the-parts are the same as in Figs. 4 and 5, except that the winding S has been removed from the boss S and the winding S has been placed beneath the winding S, the winding S 'corresponding in its functions to the winding S. If the excitation of the winding S locks the switch open, it is evident that any additional flux set up by the winding S in the same direction will still look the switch open.

the winding (Z one terminal of the switch S, the wire 13, the windings s ",s'-, and 8 in parallel, the wires 14, .15 and 16 in parallel, the contacts m m and m and the arm 0 to the negative on the contact m. The connection is broken between contacts m and m so that current ceases to flow through the wire 12, and the winding d?" is placed in series with the winding (Z Current also flows from the positive through the wire 1, the contacts (Z and d the winding (1, the solenoid S of the switch S, the wire 17, and the contacts m and m to the negative, which closes the switch S. The current through the windings 8 8 and 5 prevents their respective switches from operating until they are denergized; but on the closure of the switch S, current flows from the positive through the wire 1, the contacts (Z and d", the winding (Z the contacts of the switch S,'the operating winding S of the switch S, the wire 2, the resistances R, R and R the wire 3, the motor armature A, the wire 4, the contacts (2 and cZ the wire 5, and the series field F to the negative. This circuit connects all of the resistance in series with the motor and starts the motor at its lowest speed. As long as the master controller handle remains in the position 2, the switch S cannot operate on account of the winding S being energized. If the master controller arm 0 is moved to the position 3, the winding S is deenergized, and the switch S is allowed to close, providing the current in the winding S is below a predetermined value. Upon the closure of p the switch S, the winding S of the switch S is energized, at the same time short-cir cuiting the resistance R and causing the motor to-increase its speed. The switch S will not operate until' the-master controller arm 0 is moved to the position 4, when its winding S v is deenergized, allowing the switch to close as soon as the current in the winding S diminishes to a predetermined value. This switch then closes, energizing the winding S of. the switch S and shortcircuiting the resistance R and further increasing the speed of the motor. The switch S? is prevented from operating until the master controller arm 0 is moved to the position 5, at which time its winding S is deenergized, allowing the switch to close and short-circuiting the last section R of 'the resistance The action of the windings'S S and S on their respective switches is which may be adjusted to a predetermined Value on each switch will cause the switch to operate, as above explained, provided the windings S are deenergize'd. On moving the controller arm to the off-position, the main switch S opens, which opens the motor circuit, thereby causing all the switches TS, S and S to drop out, the reversing switch remaining in its operated position. On moving the controller handle to the position 6, the positive is connected to the point 0 through the coritacts m and 711.

and the wire 12, thereby energizing the winding (Z and short-circuiting the wind ing al which causes the reversing switch to operate, connecting its contacts (Z and cl to its contacts (Z and d, respectively.

On moving the .controller arm to position 7 the winding S is energized from the positive through the contacts m and m the wire 17, and the contacts of the reversing switch to the negative, through the wire 5 and the field F. This causes the switch S to operate, closing the motor circuit through all the starting resistance, but the current now flows through the armature in the opposite direction from that before through the following circuit: From ,the positive through the wire 11, the contacts d"? and d, the wire 4, the armature A, the wire 3, the starting resistance, the wi re 2, the operating winding of the switch S, the contacts of the switch S, the winding (Z the contacts (i and (P, the wire 5, and the series field F to the negative. The direction of current has been reversed through the winding S and it is also reversed through the windings s, 8 and 8 since the positive connection is now at the master controller. As the master switch arm is moved step by step to positions 7, 8, 9, and 10, the switches S, S and S operate as before to short circuit the starting resistance and bring the motor up to speed. On moving the master switch arm 0 to the off-position, the switch S opens the motor circuit and the accelerating switches drop out.

- If the master switch arm is moved quickly from the oii-position to position 5,the reversing switch will operate, and then the main switch S willclose, all the windings S S and S will be deenergized, but the winding S will operate the switch S only when the motor current is below a. predetermined value. The operation of this switch'energizes the operating winding of the switch S In the same manner this switch does not operate until the motor current is again below a predetermined value. Likewise when the switch S closes the operating winding of. the switch S is energized, but this switch does not close until themotor current is again reduced to a predetermined value and the acceleration of the motor has taken place automatically and in the shortest time without exceeding a safe value of motor current.

the arm of the master switch is reversed quickly to'position 6, although the winding d iis now fully energized it will not operate the reverser until the switch S has opened and the motor current actually interrupted, thereby deenergizing the winding (Z It often occurs that, if the motor circuit contains a large inductive resistance, the are at the contacts of the switch S will continue to exist for some little time until the switch has reached its maximum opening position, but the reverser with the construction shown will not operate until the arc has been extinguished and the motor current definitely interrupted. This action of preventing the operation of the reversing switch does not, therefore,- depend upon the position of the switch S, but upon the condition of whether or not current is flowing in the motor circuit.

It will be noticed that the switches S, S and S are held closed by the motor current and will, therefore, not open until the current in the motor circuit ceases to How there by preventing any are at their contacts at the opening of the switch. For the same reason the reversing switch cannot operate as long as any motor current flows, and no arc will be formed at its contacts when it is allowed to operate.

I have shown the preventive operating windings s s and 8 connected in multiple and deenergized one at a time by the movement of the master controlling handle. It will be readily understood by those skilled in the art that these windings may be con-' nected in series or in other combinations with proper connections on the master coni troller to deenergize the windings at will as the master controller handle is moved from one position to the next.

When the winding (Z is energized and the armature (l is attracted to the boss or pole (Z as hereinbefore described, the winding 6 is short-circuited, and a magnetic flux is set up through the path 0". This will cause the armature d to be attracted to the boss 6Z3.

Upon the closure of the main switch the motor current will flow through the winding (Z which is connected to set up a magnetic flux in the direction of the path 6 having the double barbed arrows. This will increase the flux tending to hold the armature in contact with the boss 6Z It now the positive connection is removed from the point 0, the two windings al and (Z are connected in series and equally excited, the winding al being so connected that it will tend to set up a flux in the path a. This flux however is opposed in the central arm of the magnetic circuit through the armature by the flux set' up by the windings (Z and J, and will be forced into the path marked a, and due to .2.

the small gap between the armature and the boss d this flux will help to hold the armature (l in contact with the boss 6Z3. It now the point should be connected to the negative main, the winding (Z would be short-circuited, and the winding a? would be fully excited. The flux Still set up by. the winding al however, will still oppose the flux set up by the winding 6 in the central arm of the circuit, and force the increased flux of the winding d to flow in the path 0 which will hold the armature in contact with the boss (Z as long as any motor current fiowsin the winding 65 If the motor current is now interrupted, the winding (Z will be deenergized and the flux set up by the winding (Z will follow the path 0 thereby attracting the armature (Z to the boss (Z and reversing the connections to the wish aiso-to point out armature. If new the motor circuit is again established, the direction of current through the winding (Z will be reversed, and the flux set up in this coil will now be in the direction shown by the path 0 which will assist the flux set up by the winding al in holding the armature in contact with the boss (Z The armature will continue to remain in this po sition as long as any motor current flows regardless of whether the windings al and (Z are excited or not. V hen the flux set up by the winding d is flowing in the path 0 any flux set up by the winding (Z which would tend to flow in the path 0 would now be opposed by the flux of. the winding J in the. central arm of the magnetic circuit, and the flux in the winding Z would be directed into the path a which would help to hold the arm (13* in contact with the loosed; Generally speaking, whenever the winding d is deenergized the armature Z will be attracted to that boss whose winding has the excess excitation, but when the Winding CZ is energised it will hold the armature in contact with the boss to which it has been previously attracted, and the windings d and (i then both operate to hold the armature in that po- Sition.

Assuming that the winding al has been energized and the armature (Z attracted to the boss (Z if the windings (Z and (3 are now connected in series, the flux set up by the winding (Z will Flow in the path 0", and the flux set up by the'winding al will tend to flow in the path 6 but since the reluctance of the path 0 will be much less than that of the path 0 due to the armature [5 being in contact with the boss 05 the iiux in the cen tral arm of the magnetic circuit set up by the winding (i and the from the winding (Z will be directed into the path 0 and the two windings, therefore, tend to hold the armature (51 against the boss d. l have pointed out before tl'iat this effect tal when the winding, a is she;

that tho take place when only the two windings (Zn and (Z are energized in series, which occurs when the master controller handle in Fig. 1 is moved to the position 2, thus disconnecting the wire 12 from the negative main. The advantage of this action is that after the reverser has operated, the two windings can be thrown in series, maintaining an proximately the same pressure between the reverser contacts, but cutting down the amount of heating in the operating wind!- ings.

I claim 1. In a magnetically operated switch, a pair of contacts, a movable member adapted to move one of said contacts and biased to an inoperative position with said switch contacts separated, two windings for said.

switch, and means whereby when one winding is energized at a certain value in ampere turns it assists in biasing the movable member to inoperative position, and when energized at a lower value in ampere turns causes the movable member to move to an operative position, and whereby when the other winding is energized the movable member is pro vented from operatin 2. In aswitch, a pair of switch contacts,

amovable member adapted to move one of said contacts and biased to an inoperative position with the said contacts separated, two windings for said switch, and means whereby, when one of the windings is energized alone, the contacts will close against the said bias, and whereby, when the second winding is energized above a predcterin value after the contacts have been closcn, contacts are caused to open.

3. In a switch, a pair of contacts, a movable member adapted to move one of the contacts and normally in inoperative position with the contacts separated, two windings for the switch, and means whereby the movable member closes the contacts only when the current in one of the windings is below a predetermined value in ampere turns, and whereby, when the second winding is energized, .the movable member is held in its inoperative position.

i. In a switch, a movable switch member, a winding therefor, means whereby the switch member is prevented from movement when the current in the winding is above a predetermined value and caused to move when the current in the winding falls to the said value, and an electro-magnetic means associated with the first-named means for preventing the movement of the said member when the current in the said winding has fallen to the said predetermined value.

5. A controlling device for electric circuits comprising a movable switch member, an'electromagnet cooperating therewith to either close the switch or hold it open, means whereby the switch is held open by the magnet when the current through the magnet Signed at Cleveland, Ohio, this 21st day is relatively high and closed by the magnet of September, A. D. 1910.

when the current falls to a predetermined JAY HALL. value, and electromagnetic means for con- Witnesses: 5 trolling the closing of said switch after the R. H. BENNE'IT,

current has fallen to" a predetermined value. DIEMER. 

